/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.file;

import java.util.Collection;
import java.util.TreeMap;

import com.android.dx.rop.cst.Constant;
import com.android.dx.rop.cst.CstType;
import com.android.dx.rop.type.Type;
import com.android.dx.util.AnnotatedOutput;
import com.android.dx.util.Hex;

/**
 * Type identifiers list section of a {@code .dex} file.
 */
public final class TypeIdsSection extends UniformItemSection {

	/**
	 * {@code non-null;} map from types to {@link TypeIdItem} instances
	 */
	private final TreeMap<Type, TypeIdItem> typeIds;

	/**
	 * Constructs an instance. The file offset is initially unknown.
	 * 
	 * @param file
	 *            {@code non-null;} file that this instance is part of
	 */
	public TypeIdsSection(DexFile file) {
		super("type_ids", file, 4);

		typeIds = new TreeMap<Type, TypeIdItem>();
	}

	/** {@inheritDoc} */
	@Override
	public Collection<? extends Item> items() {
		return typeIds.values();
	}

	/** {@inheritDoc} */
	@Override
	public IndexedItem get(Constant cst) {
		if (cst == null) {
			throw new NullPointerException("cst == null");
		}

		throwIfNotPrepared();

		Type type = ((CstType) cst).getClassType();
		IndexedItem result = typeIds.get(type);

		if (result == null) {
			throw new IllegalArgumentException("not found: " + cst);
		}

		return result;
	}

	/**
	 * Writes the portion of the file header that refers to this instance.
	 * 
	 * @param out
	 *            {@code non-null;} where to write
	 */
	public void writeHeaderPart(AnnotatedOutput out) {
		throwIfNotPrepared();

		int sz = typeIds.size();
		int offset = (sz == 0) ? 0 : getFileOffset();

		if (sz > 65536) {
			throw new UnsupportedOperationException("too many type ids");
		}

		if (out.annotates()) {
			out.annotate(4, "type_ids_size:   " + Hex.u4(sz));
			out.annotate(4, "type_ids_off:    " + Hex.u4(offset));
		}

		out.writeInt(sz);
		out.writeInt(offset);
	}

	/**
	 * Interns an element into this instance.
	 * 
	 * @param type
	 *            {@code non-null;} the type to intern
	 * @return {@code non-null;} the interned reference
	 */
	public TypeIdItem intern(Type type) {
		if (type == null) {
			throw new NullPointerException("type == null");
		}

		throwIfPrepared();

		TypeIdItem result = typeIds.get(type);

		if (result == null) {
			result = new TypeIdItem(new CstType(type));
			typeIds.put(type, result);
		}

		return result;
	}

	/**
	 * Interns an element into this instance.
	 * 
	 * @param type
	 *            {@code non-null;} the type to intern
	 * @return {@code non-null;} the interned reference
	 */
	public TypeIdItem intern(CstType type) {
		if (type == null) {
			throw new NullPointerException("type == null");
		}

		throwIfPrepared();

		Type typePerSe = type.getClassType();
		TypeIdItem result = typeIds.get(typePerSe);

		if (result == null) {
			result = new TypeIdItem(type);
			typeIds.put(typePerSe, result);
		}

		return result;
	}

	/**
	 * Gets the index of the given type, which must have been added to this
	 * instance.
	 * 
	 * @param type
	 *            {@code non-null;} the type to look up
	 * @return {@code >= 0;} the reference's index
	 */
	public int indexOf(Type type) {
		if (type == null) {
			throw new NullPointerException("type == null");
		}

		throwIfNotPrepared();

		TypeIdItem item = typeIds.get(type);

		if (item == null) {
			throw new IllegalArgumentException("not found: " + type);
		}

		return item.getIndex();
	}

	/**
	 * Gets the index of the given type, which must have been added to this
	 * instance.
	 * 
	 * @param type
	 *            {@code non-null;} the type to look up
	 * @return {@code >= 0;} the reference's index
	 */
	public int indexOf(CstType type) {
		if (type == null) {
			throw new NullPointerException("type == null");
		}

		return indexOf(type.getClassType());
	}

	/** {@inheritDoc} */
	@Override
	protected void orderItems() {
		int idx = 0;

		for (Object i : items()) {
			((TypeIdItem) i).setIndex(idx);
			idx++;
		}
	}
}
